// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_REGISTRY_H_
#define CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_REGISTRY_H_

#include <map>
#include <memory>
#include <set>
#include <vector>

#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/strings/string16.h"
#include "content/common/content_export.h"
#include "content/common/service_worker/service_worker_status_code.h"

class GURL;

namespace IPC {
class Message;
class Sender;
}

namespace content {

class EmbeddedWorkerInstance;
class MessagePortMessageFilter;
class ServiceWorkerContextCore;

// Acts as a thin stub between MessageFilter and each EmbeddedWorkerInstance,
// which sends/receives messages to/from each EmbeddedWorker in child process.
//
// Hangs off ServiceWorkerContextCore (its reference is also held by each
// EmbeddedWorkerInstance).  Operated only on IO thread.
class CONTENT_EXPORT EmbeddedWorkerRegistry
    : public NON_EXPORTED_BASE(base::RefCounted<EmbeddedWorkerRegistry>) {
public:
    typedef base::Callback<void(ServiceWorkerStatusCode)> StatusCallback;

    static scoped_refptr<EmbeddedWorkerRegistry> Create(
        const base::WeakPtr<ServiceWorkerContextCore>& contxet);

    // Used for DeleteAndStartOver. Creates a new registry which takes over
    // |next_embedded_worker_id_| and |process_sender_map_| from |old_registry|.
    static scoped_refptr<EmbeddedWorkerRegistry> Create(
        const base::WeakPtr<ServiceWorkerContextCore>& context,
        EmbeddedWorkerRegistry* old_registry);

    bool OnMessageReceived(const IPC::Message& message, int process_id);

    // Creates and removes a new worker instance entry for bookkeeping.
    // This doesn't actually start or stop the worker.
    std::unique_ptr<EmbeddedWorkerInstance> CreateWorker();

    // Called from EmbeddedWorkerInstance, relayed to the child process.
    ServiceWorkerStatusCode StopWorker(int process_id,
        int embedded_worker_id);

    // Stop all active workers, even if they're handling events.
    void Shutdown();

    // Called back from EmbeddedWorker in the child process, relayed via
    // ServiceWorkerDispatcherHost.
    void OnWorkerReadyForInspection(int process_id, int embedded_worker_id);
    void OnWorkerScriptLoaded(int process_id, int embedded_worker_id);
    void OnWorkerThreadStarted(int process_id,
        int thread_id,
        int embedded_worker_id);
    void OnWorkerScriptLoadFailed(int process_id, int embedded_worker_id);
    void OnWorkerScriptEvaluated(int process_id,
        int embedded_worker_id,
        bool success);
    void OnWorkerStarted(int process_id, int embedded_worker_id);
    void OnWorkerStopped(int process_id, int embedded_worker_id);
    void OnReportException(int embedded_worker_id,
        const base::string16& error_message,
        int line_number,
        int column_number,
        const GURL& source_url);
    void OnReportConsoleMessage(int embedded_worker_id,
        int source_identifier,
        int message_level,
        const base::string16& message,
        int line_number,
        const GURL& source_url);

    // Keeps a map from process_id to sender information.
    void AddChildProcessSender(
        int process_id,
        IPC::Sender* sender,
        MessagePortMessageFilter* message_port_message_filter);
    void RemoveChildProcessSender(int process_id);

    // Returns an embedded worker instance for given |embedded_worker_id|.
    EmbeddedWorkerInstance* GetWorker(int embedded_worker_id);

    // Returns true if |embedded_worker_id| is managed by this registry.
    bool CanHandle(int embedded_worker_id) const;

    MessagePortMessageFilter* MessagePortMessageFilterForProcess(int process_id);

private:
    friend class base::RefCounted<EmbeddedWorkerRegistry>;
    friend class MojoEmbeddedWorkerInstanceTest;
    friend class EmbeddedWorkerInstance;
    friend class EmbeddedWorkerInstanceTest;
    FRIEND_TEST_ALL_PREFIXES(EmbeddedWorkerInstanceTest,
        RemoveWorkerInSharedProcess);

    using WorkerInstanceMap = std::map<int, EmbeddedWorkerInstance*>;
    using ProcessToSenderMap = std::map<int, IPC::Sender*>;
    using ProcessToMessagePortMessageFilterMap = std::map<int, MessagePortMessageFilter*>;

    EmbeddedWorkerRegistry(
        const base::WeakPtr<ServiceWorkerContextCore>& context,
        int initial_embedded_worker_id);
    ~EmbeddedWorkerRegistry();

    ServiceWorkerStatusCode Send(int process_id, IPC::Message* message);

    // Called when EmbeddedWorkerInstance is ready for IPC. This function
    // prepares a route to the child worker thread.
    // TODO(shimazu): Remove this function once mojofication is completed.
    void BindWorkerToProcess(int process_id, int embedded_worker_id);

    // RemoveWorker is called when EmbeddedWorkerInstance is destructed.
    // |process_id| could be invalid (i.e. ChildProcessHost::kInvalidUniqueID)
    // if it's not running.
    void RemoveWorker(int process_id, int embedded_worker_id);
    // DetachWorker is called when EmbeddedWorkerInstance releases a process.
    // |process_id| could be invalid (i.e. ChildProcessHost::kInvalidUniqueID)
    // if it's not running.
    void DetachWorker(int process_id, int embedded_worker_id);

    EmbeddedWorkerInstance* GetWorkerForMessage(int process_id,
        int embedded_worker_id);

    base::WeakPtr<ServiceWorkerContextCore> context_;

    WorkerInstanceMap worker_map_;
    ProcessToSenderMap process_sender_map_;
    ProcessToMessagePortMessageFilterMap process_message_port_message_filter_map_;

    // Map from process_id to embedded_worker_id.
    // This map only contains starting and running workers.
    std::map<int, std::set<int>> worker_process_map_;

    int next_embedded_worker_id_;
    const int initial_embedded_worker_id_;

    DISALLOW_COPY_AND_ASSIGN(EmbeddedWorkerRegistry);
};

} // namespace content

#endif // CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_REGISTRY_H_
